Video Live Wallpaper, Part 1

I took a freelance coding job asking me to code a Video Live Wallpaper. Sounds easy, right? Just create a Live Wallpaper and tell Android to play a video. How hard can that be? Unfortunately, in Android 2.1, 2.2, (and possibly 2.3), you can’t play videos in a Live Wallpaper. Well, you can but it’s something you have to program yourself. And that’s the problem. This seemingly trivial project is way harder than it looks. While not exactly rocket science, it’s not exactly a “walk in the park” either.

Let me explain exactly what’s involved: (1) you have to write your own decoder, which means that (2) you need to work with the NDK.

In this series, I’ll explain how I got video working in a Live Wallpaper using FFmpeg and OpenGL. The result is still a proof of concept but it’s more than enough to get you started.

We’re using FFmpeg because we are not writing our own video decoder. We could, but we shouldn’t. That’s poor programming practice.

Download and install the NDK. If you’re working in the command line, add it to your PATH.
Read an introductory tutorial for the NDK. This one is good. It’ll take you 5 minutes. Take a look at the Hello World app that comes with the NDK.
Dowload FFmpeg. We’re going to use bambuser’s version for Android. Download client version 1.3.7 to 1.3.10. That’s for NDK r5, which is what I used.
Unpack the bambuser archive into your JNI folder. (What’s the JNI folder? You did read the NDK tutorial, right?)
Extract the FFmpeg source code. cd into the ffmpeg-android folder and run extrach.sh.

Modify build.sh for your project. The first thing is to re-enable all the FFmpeg options. (By default, bambuser disables everything but one codec.) Secondly, add your package name using the -soname-prefix. (See the sample build file below).

#!/bin/bash
if [ "$NDK" = "" ]; then
        echo NDK variable not set, assuming ${HOME}/android-ndk
        export NDK=${HOME}/android-ndk
fi

SYSROOT=$NDK/platforms/android-3/arch-arm
# Expand the prebuilt/* path into the correct one TOOLCHAIN=`echo $NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/*-x86`
export PATH=$TOOLCHAIN/bin:$PATH

rm -rf build/ffmpeg
mkdir -p build/ffmpeg
cd ffmpeg

# Don't build any neon version for now for version in armv5te armv7a; do

        DEST=../build/ffmpeg
        FLAGS="--target-os=linux --cross-prefix=arm-linux-androideabi- --arch=arm"
        FLAGS="$FLAGS --sysroot=$SYSROOT"
        FLAGS="$FLAGS --soname-prefix=/data/data/YOUR.PACKAGE.NAME/lib/"
        FLAGS="$FLAGS --enable-shared --disable-symver"
        FLAGS="$FLAGS --enable-small --optimization-flags=-O2"
        FLAGS="$FLAGS --enable-version3 --enable-nonfree"
        FLAGS="$FLAGS --disable-doc --disable-ffserver"

        case "$version" in
                neon)
                        EXTRA_CFLAGS="-march=armv7-a -mfloat-abi=softfp -mfpu=neon"
                        EXTRA_LDFLAGS="-Wl,--fix-cortex-a8"
                        # Runtime choosing neon vs non-neon requires                         # renamed files                         ABI="armeabi-v7a"
                        ;;
                armv7a)
                        EXTRA_CFLAGS="-march=armv7-a -mfloat-abi=softfp"
                        EXTRA_LDFLAGS=""
                        ABI="armeabi-v7a"
                        ;;
                *)
                        EXTRA_CFLAGS=""
                        EXTRA_LDFLAGS=""
                        ABI="armeabi"
                        ;;
        esac
        DEST="$DEST/$ABI"
        FLAGS="$FLAGS --prefix=$DEST"

        mkdir -p $DEST
        echo $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" > $DEST/info.txt
        ./configure $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" | tee $DEST/configuration.txt
        [ $PIPESTATUS == 0 ] || exit 1
        make clean
        make -j4 || exit 1
        make install || exit 1

done

Notes: (1) Run ./configure --help from the command line for more options. (2) Make sure to enable the file protocol. You need that to open files on the phone. (3) I enabled the non-free codecs, which may or may not be compatible with the license for your project. (4) I’m not sure whether or not you need to add the package name to the libraries. I haven’t tested it out without the package name.

Compile FFmpeg. Run build.sh from the command line.
Go get some coffee. When you return you’ll have shared libraries (.so files) of FFmpeg. Why shared libraries and not static libraries? If I recall correctly, with NDK, you need to use shared libraries to build other modules.
Add the libraries to the android project. Since you just compiled them, you need to add them as prebuilt shared libraries. This way you don’t recompile them each time you make changes to your NDK code. There are many ways to add these libraries to your project. Here’s one that works. Add this to the Android.mk file of the root JNI folder:

LOCAL_PATH := $(call my-dir)

MY_LIB_PATH := ffmpeg-android/build/ffmpeg/armeabi/lib

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavcore
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavcore.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavformat
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavformat.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavcodec
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavcodec.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavdevice
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavdevice.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavfilter
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavfilter.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavutil
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavutil.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libswscale
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libswscale.so
include $(PREBUILT_SHARED_LIBRARY)

In the next part, we’ll actually do something with FFmpeg within Android.

UPDATE: To load a video from the SD card in FFmpeg, you need to use a file name of the form file:/sdcard/FILENAME.

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About this entry

You’re currently reading “Video Live Wallpaper, Part 1,” an entry on Ikaruga 2

Published:: June 15, 2011 / 12:49 am

Category:: Technology

Tags:: Android, Linux, Live wallpaper, NDK, OpenGL

Video Live Wallpaper, Part 2 « Ikaruga 2 6.15.11 / 8am

[...] Part 1, we compiled the FFmpeg library for android. In this post, we’ll actually do something with [...]

Video Live Wallpaper, Part 3 « Ikaruga 2 7.13.11 / 8am

[...] also: Part 1, Part 2 Leave a [...]

Video Live Wallpaper, Part 4 « Ikaruga 2 8.10.11 / 9am

[...] 1, Part 2, Part 3 Leave a [...]

Tristus1er 10.14.11 / 12pm

I have tryed on Windows : compilation fail :
C compiler test failed.
I have installed Linux : more problems :
–soname-prefix : parameter unknown
–optimization-flags : parameter unknown
and then the same message :
C compiler test failed.
I have created a tmp folder in the source folder (seen on some forum), installed build-essential, but nothing work.
I have tried to use the precompiled libraries … but impossible to compile le las one (video.c).
I have seen that many people has problems to compile ffmpeg, your tutorial is very nice, so maybe it would be a nice place to explain how to fix all the possible problems here ?
Thank you.

ikaruga2099 10.21.11 / 5pm

How are you compiling video.c? Just to be clear and I just noticed that these instructions aren’t, you have to: (1) compile FFmpeg using the build script shown here, (2) run “ndk-build” from the project root directory. I just did that and everything compiled fine.

Costa 1.25.12 / 9pm

Is it possible to compile FFmpeg in windows ? I can develop no problem – invoke NDK-BUILD from android-ndk-r7 for Windows – but I come up short when trying to compile FFmpeg through Cygwin.
/ffmpeg/config.log always list some sporadic “No such file or directory” followed by “no input files” “C compiler test failed” no matter the workaround I find for each error.
Is there any way to avoid these problems ?
Thanks.

config.log example:
…
type mktemp
mktemp is /usr/bin/mktemp
check_ld
check_cc
BEGIN /tmp/ffconf.m5aXwDgN.c
1 int main(void){ return 0; }
END /tmp/ffconf.m5aXwDgN.c
arm-linux-androideabi-gcc –sysroot=/cygdrive/c/Android/android-ndk-r7/platforms/android-3/arch-arm -c -o /tmp/ffconf.34Ny9Kgu.o /tmp/ffconf.m5aXwDgN.c
arm-linux-androideabi-gcc.exe: /tmp/ffconf.m5aXwDgN.c: No such file or directory

arm-linux-androideabi-gcc.exe: no input files

C compiler test failed.

Tristus1er 1.25.12 / 10pm

@ikaruga2099 => Thanks for your help
@Costa => I have tryed under windows … it was too hard for me … I have installed a virtual machine running Ubuntu and it’s was better thanks to this great tutorial
So I run windows, and I can compile ffmpeg.

For me it’s the best way to do if running under windows.

zelizeliOri 2.7.12 / 11pm

Thanks for the cool tutorial.

How can i get a hold of your for possible custom coding project for a video live wallpaper android app.

again, very cool!

Tristus1er 2.8.12 / 10am

Hello zelizeliOri
If you need some help about the customisation of this code, I might help you.
Please let me your email, and I’ll contact you.

Best regards.

zelizeliOri 2.8.12 / 7pm

zelizeli@yahoo.com

Ravi 3.5.12 / 11am

hi i’m making use of your code live video livewallpaper sample
nut i’m getting error
im usinf windows xp
cygwin

pls help

Sorry for my engilish

zelizeliOri 2.14.12 / 6pm

does anyone in the blog know of a developer that would be interested for hire to work on a live video wallpaper project for android.

looking forward.

Change color-depth in FFMpeg 3.20.12 / 11am

[...] I try play video in live wallpaper using Android NDK and FFMpeg library. I was guided by: http://ikaruga2.wordpress.com/2011/06/15/video-live-wallpaper-part-1/ [...]

Marcelo 6.5.12 / 7pm

Hi Guys, I would like to know if has some tutorial to show how create a video from image using ffmpeg + Android…

ikaruga2099 6.27.12 / 12am

Not sure exactly what you mean by that. You can to take some images, then turn them into a video? I’m assuming you want to create an app with that functionality. If I recall, ffmpeg does have that functionality. Search for the C code then call it via the NDK using this as a base.

Vishal 7.22.12 / 4pm

Nice document.

THANKS ikaruga2099.

I have successfully run the Video as Live wallpaper. I used Ubuntu to build the app.

I seen the below issues :
1. The wallpaper set to black screen on HTC Desire (Smartphone) for first time, I need to set the same wallpaper again then only i see the video. On other devices its working from first time itself.

2. Set the video wallpaper on home screen and then set the another live wallpaper from available list. Its working fine. Now again set the video live wallpaper. Seen some scratched image which is not running sometimes running with similar kind of scratched images.

3. In tablet, after changing orientation to landscape the Video changes the orientation but successfully with changed width and height. Now change the orientation to portrait again I seen the video with orientation changed but with half height and width full as per device width. Means the video is rendering from half of the screen.

Can you please let me know on this?

Please help me in this.

Thanks,
vishsoft

ikaruga2099 7.22.12 / 5pm

Unfortunately, this live wallpaper has a lot of bugs and probably needs a fresh rewrite. However, I haven’t had the time to update this. If I recall there’s an issue when you change the orientation. The app is supposed to re-load everything but for some reason the memory never gets released, resulting in video playing half-screen.

If you want to work on this together, I’ll see if I can squeeze some time in

1. Vishal 7.22.12 / 5pm
  
  Thanks for your reply.
  
  Yes I am interested to get this worked atleast orientation.
  
  I seen on code in onDestroy nothing is released from Renderer only called release method of renderer and release is empty.
  
  I will update you once I found something by adding logs on files to get the width, height and all required parameters.
  
  I think my 2 issue on above comment might be caused because of old memory images (memory never gets released).
  
  We will work.
  
  Thanks,
  vishsoft

How to play video as live wallpaper android? : Android Community - For Application Development 1.10.13 / 11am

[...] will save you some time. A tutorial on Video Live Wallpaper here.Go through part 1 -4. And here is a link of the project code. Hope it will help you get [...]

mstudios 3.20.13 / 12pm

I am looking for a programmer to do the same thing, code a video live wallpaper for android tablets. I could not find an email address on your blog, but please contact me if you are interested.

Vishal 3.20.13 / 12pm

Hello mstudios,

I am interested to do your work. contact me spk : vishal.bodkhe

Thanks,
vishsoft

Tristan 4.1.13 / 10am

Hello,
I have used this tutorial to deliver Video Live Wallpapers on Google Play.
I can help you if you want: tristus1er [at] gmail [dot] com

Chris 4.1.13 / 1am

Hi, Thanks for this tutorial. Since you specified Android 2.3 can’t play videos on wallpaper.
Do you think, the latest versions of android support running videos on live wallpaper ?
Pls let me know.
Thanks

Tristan 4.1.13 / 10am

Android can play vidéos (using this Video Live Wallpaper since 2.1: till support of Live Wallpapers )

1. Chris 4.1.13 / 2pm
  
  Thanks for you reply. I am new to Android App Development. May be I am missing some point.
  I like to know, is there a direct API in later versions of android like 4.1, which supports running videos in live wallpaper. Instead of programming the functionality on our own using NDK.

fiphiker 5.21.13 / 5pm

Hello, could you help me? I tryed run this project
https://github.com/frankandrobot/FFvideoLiveWallpaper, but on devices
write error in application, why?
Thanx.

Ikaruga 2

Video Live Wallpaper, Part 1

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